To stack or not to stack

John K wrote:

mawyatt2002 wrote:

Lighting for stacking can be extremely challenging with certain subjects, more so than for a single image, and especially so when doing Stack & Stitch images.

This is where you and I are going to have to agree to disagree. When you stack a scene you are using only a small section of a single slice of the frame, the section that's in focus. So the the exposure over all of those sections is not additive. It's just one exposure, with the areas that are in focus blended.

So it doesn't matter if you're shooting single frames or stacks the exposure, and dealing with highly reflective areas, is the same.

It's not quite that simple. The stacking algorithms don't just use the in-focus thin ribbon, Rik Littlefield author of Zerene is better to address this than me, you can review some of the details at his Zerene web site.

During a stack the illumination needs to be consistent across the entire captures, any variation whatsoever will show up as "focus banding". Since stacking involves moving the lens or subject, even when stacking using the lens focus, something in the lens is moving and thus changing the lens characteristics, and the lighting details become important. Getting the right diffusion and exposure for a single image may not yield a good result when stacked, especially a deep stack.

Anyway, Rik, Lou, Ray and others over at PM have discussed this topic in detail, including it's effect on different subjects, including something that on the surface (pun intended) seems straightforward, coin images. Short story, stacking lighting is more difficult, and S&S even more so.

Best,